teemcp

As mdm said,
 
A minus value in highlight tone darkens the highlights (and the opposite for a positive value - ie lightens the highlights)
 
A minus value in shadow tone lightens the shadows (and the opposite for a positive value - ie darkens the shadows)
 
If you set the camera to shoot RAW, then you can use the in camera raw convertor to experiment with these settings, and create a series a jpegs with different settings applied and chose the one you like the most

If you set the focus mode switch to Manual, the AF-L button will do back button focus.  If you leave it in S or C, BBF will not work.

http://www.fujixseries.com/forums/topic/1521-case-of-the-disappearing-viewfinder-grid/
 
Maybe this can help . . .